Building Durability into High Performance Buildings

Building Durability into
High-Performance Buildings
Paul Malko
Foard Panel
Chesterfield, NH
Presentation Rules
 Ask
 This
questions any time.
is a conversation not a lecture.
© 2015
Disclaimer
This presentation contains the best of my
understanding and was developed using
data gathered from the field. I've done my
level best to be “data driven”. However, I
learn new things every day, so I reserve the
right to be wrong.
© 2015
“Normal Performance” Buildings
Built by Professionals...
 Are
safe.
 Are
designed and built to suit the intended use.
 Are
good investments for the clients.
 Have
moderate utility costs.
 Require
 Have
only modest annual maintenance.
an expected lifetime of 30+ years.
© 2015
“High Performance” Buildings Built
by Professionals...
 Are
safe and durable.
 Are
designed and built to be comfortable for
the intended use.
 Are
excellent investments for the clients.
 Have
low utility costs.
 Require
 Have
only little annual maintenance
an expected lifetime of 100+ years
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Holy Triangle, Part 1
Customer Expectations
Good
Pick
any 2
Fast
Cheap
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Holy Triangle, Part 2
Durability
Design
Requires
all 3
Materials
Construction
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How to Make High Performance
Buildings Durable
Accept that high-performance
buildings are different...
Different Materials
Different Heat Loss
Different Air Infiltration
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Different Materials
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Lower Heat Loss



Reduces Fuel
Consumption
Slows drying
Permeance only applies
to water vapor
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Low Air Infiltration

Requires ventilation for IAQ

Slows drying
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Holy Triangle, Part 2
Durability
Design
Requires
all 3
Materials
Construction
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Design

Architecture

Structure

Mechanical

Detailing

Material Specification
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Holistic Design
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Holistic Design
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Design of Water Concentration
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Design of Water Concentration
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Roof/Dormer Design
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Structural Example: Snow
A properly designed building will never, ever need
it's roof shoveled
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Structural Example: Snow
A properly designed
building will never,
ever need it's roof
shoveled
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Design - Hidden Gutters
Coast of Maine
 Construciton:
Timber Trusses
Urethane Panels
Peel-&-Stick
Cedar Shingles
Soldered Copper
Gutters
 6 years old

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Hidden Gutter Repair
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Design - Water Concentration
Construction - Diverters, Flashing
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Design for Mechanicals
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Design Air Sealing For Shrinking Timber
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Holy Triangle, Part 2
Durability
Design
Requires
all 3
Materials
Construction
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Material Compatibility
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Many high-performance
envelopes have limited water
capacitance.
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Limited Water Capacitance



SIPs
Stick & Spray
Foam
Stick & Flash/Batt*
Detail Appropriately
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Some Materials Are Not Compatible
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Holy Triangle, Part 2
Durability
Design
Requires
all 3
Materials
Construction
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What?
Construction
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Construction
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Design & Construction
Design for Mechanicals
 Construction with
Structural Sympathy

Be willing to ask designers/GCs
for a plan!
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Construction
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High Performance Buildings
are “Special”

Reduced heat loss

Less energy to evaporate water

Water stays liquid longer

Requires more conservative
detailing
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“Normal” Detailing of HighPerformance Buildings
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“Normal” Detailing of HighPerformance Buildings
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Avoiding Disaster

Good Design

Compatible Materials


Correct Building Science
Quality Construction

High-Performance Detailing
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Design





Little/No WaterConcentration
Large Overhangs
Large Grade-to-Sill
Distance
Vented Roof and
Walls
No Roof Rotters
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Design & Detailing
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Building Science - Dew Point
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Dew Point

Pure Water Vapor: Steam

Water Disolved in Air: Humidity

Relative Humidty (RH)
actual water in volume of air
- vs © 2015
Dew Point

The amount of water that can be
disolved in air depends on
temperature

Lower temp air holds less water

Higher temp air holds more
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Building Science - Dew Point
Air: 70°F, 40% RH
Beer: 35°F
Surface of Glass: 36°F
Air: 40°F --> 100% RH
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Dew Point
Indoor Air: 70°F & 40% RH
R21 Infill
R10 Continuous
Outdoor Air: 20°F
35°F & 100% RH
(Condensation)
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Solutions


The air control layer must be
warmer (farther interior) than the
dew point.
Don't trap wood between
hydrophobic layers
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Solutions:
Interior-Side Air sealing
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Solutions: More Air Sealing
Solutions: Testing
Solutions:
Let Everything Dry
Solutions:
Design is more than architecture

2 choices

Design

Guess
Solutions:
Intuition Doesn't Work
equal

12,000 sqft

200 kBTU/hr

16' clear

500 W max

170kBTU/hr @ D. D.
Solutions:

Design FIRST

Build SECOND
Design First


Design = Decision-Making

Architectural

Structural

Mechanical
Document & Review
Solutions

Materials, techniques, and
details are all climate
dependent.
Solutions

Beware of marketing claims

Do your own critical thinking

Beware of group-think

At one time, everyone thought
asbestos was great, too.